Alarm clock



Nov. 28, 1961 A. KOPP ALARM CLOCK Filed July 20, 1956 IOSc fvzvevz ok B Antv: ho o b mzz United States Patent Ofifice Patented Nov. 28, 1961 Claims priority, application Germany July 22, 1955 3 Claims. (Cl. 58--21.12)

The invention relates to alarm clocks which produce alarm signals of different durations, in that initially the signal is produced by single hammer strokes and only after a certain time has elapsed is the periodicity of the hammer strokes increased to produce a continuously sounding alarm signal. In particular, the invention constitutes an improvement of the alarm clock mechanism according to application Serial No. 366,836, filed July 8, 1953, now PatentNo. 2,777,278 issued January 15, 1957, wherein a control lever is provided which determines the rate of the hammer strokes and is itself timed by the clock movement, and also there is provided a control disc carried by the shaft of the alarm mechanism spring with which it is frictionally coupled and having two cam sections and a damping abutment. The control lever and the control disc cooperate in such a manner that immediately the starting mechanism of the alarm mechanism has been tripped, a first cam section and a damping abutmentl become operative with the result thatthe control lever can cooperate with a star-shaped cam wheel. The latter is mounted on a shaft provided in the clock movementand extends the period of time between each out ward movement of the alarm hammer towards the gong whereby at first the damping abutment catches the hammer before it strikes the gong. The damping abutment is arranged over a shorter arc than the first section of the control cam so that, after a few strokes, the damping abutment passes out of the range of the alarm hammer so that it can strike the gong, during which operation, however, the first control cam section still remains operative. :The clock movement however determines the frequency of the hammer strokes through the intermediary of the above-mentioned control lever. After a certain number of single strokeshave been struck, the second cam section becomes operative in that it lifts the control leverout of the range of the cam star wheel coordinated th reto on the time mechanism shaft and moves it into an inoperative position with the result that the timing of the hammer strokes is left entirely to the alarm mechanism, that is, this produces a continuously sounding alarm signal as it runs down.

v Experience has shown that in the case of alarm clocks which when sounding the alarm initially only produce single strokes, and particularlyin the case of alarm clocks according to said patent, the alarm mechanism is cut out already afterthe first, second or third hammer stroke and then again must be fully wound again. In this case it can happen that when winding the alarm to the full extent, a pawl of the spring locking mechanism is so situated in relation 'to the ratchet wheel that precisely when the spring shaft cannot be turned any further, that is when again contacts against the side of the returning tooth. The result of this is that the abutment on the cam disc, which determines the initial position by striking against a rigid counter abutment when the alarm mechanism is being wound, moves more or less way from this counter abutment. If the alarm mechanism is cut out after the first, second or third hammer stroke, the spring will not yet be unwound a distance corresponding to one ratchet tooth pitch, so that the next time the alarm mechanism is wound the spring core shaft will not be turned permanently, that is, it cannot be turned sufliciently far to enable another tooth to engage the pawl but returns to its initial position. There is however a clearance between the rigid abutment and the abutment nose of the cam disc which may be almost equal to two tooth pitch. Furthermore there is also the idle movement resulting from the fact that the pawl must havea certain amount of return play for carrying out its function. The three aforementioned causes, added together, may result in that, when winding to the fullest extent, the abutment nose on the control disc may come to a standstill away from its rigid abutment so that the damping stage, or possibly the total stage of single hammer strokes of the alarm, will fail.

In order to overcome this objection it is proposed according to the invention, to provide a setting means accessible from outside the ca e and coupled with the cam disc, with the aid of which means the disc can be moved into contact with its abutment. For this purpose a sleeve is preferably slipped loosely onto the shank of the alarm winding key and provided with a gripping flange or indicator and with a recess at its inner end for receiving a coupling pin fixed in the cam disc. 1

Other features and objects of the invention will be come apparent from the following description of one form of construction when considered in connection with the accompanying drawing. While omitting the constructional parts which are not necessary for the invention, the drawing shows on an enlarged scale in;

FIGURE 1 a rear side elevation the constructional parts serving for cont-rolling the-rate of the hammer strokes arranged in the movement of an alarm clock, and

FIG. 2 a top plan view of FIG. 1 with a part in section.

The frame of'the alarm mechanism is designated by 100, the alarm spring shaft by 101, the alarm escapement shaft by 102 with its escape lever 103, the hammer carrier by 104 and the hammer by 105. A two-armed lever 106 is oscillatable and rotatable on the alarm spring shaft; and it has an open fork-shaped bearing 106a and a V-shaped spring 107 one end of which rests against the alarm spring shaft 101 for approximately whereas its other end hooks into the lever 106 at 106b, holding this lever in position and shifting its point 1060 within the range of a star wheel 108 mounted on an abutment plate 109 incorporated in the time mechanism.

For coupling the control lever 106 with the alarm striker hammer 105 an abutment plate 109 is fixed on the hammer and a recess 106d is provided on the control lever 106. The abutment plate 109 has an aperture through which an extension 107a of the spring 107 extends for imparting such initial tension to the spring 107 that it tends to swing the control lever 106 out of the range of the star wheel 108 when the control lever 106 is not forced by the alarm hammer above the abutment plate 109 into the range of the star wheel. The control lever 106 cooperates with the alarm hammer 105 and the time movement in the following manner:

By tripping the alarm mechanism for setting the alarm time, the alarm escapement shaft 102 is released in Lknown manner. In the example illustrated the escape wheel tooth 118 presses against the pallet end 103a of the alarm escape lever and thereby imparts to the alarm escapement shaft 102 a rotary movement in counterclockwise direction. Thereby the abutment plate 109 on the alarm hammer 105 strikes against the edge 106d of a recess in the control lever 106 and swings the control lever also in counterclockwise direction with the result that the finger 106a of the control lever comes into contact with one of the arms or teeth of the cam star wheel 108 and is only released therefrom when the co ordinated time movement shaft 119 has turned through a certain angle in a given time. The finger 1060 of the control lever 106 can then drop off the star wheel 108, whereupon the hammer 105 carries out a short movement in counterclockwise direction, that is a half swing in the opposite direction towards the gong and returns into the position shown in FIG. 1, that is, the point 106a of the control lever is again caught by one of the teeth or arms of the star wheel, and so forth.

The spring 107a serves the purpose to move the control lever 106 in the direction of the star wheel 109 as shown in Patent No. 2,777,278.

Looking toward the rear plate of the movement, the control disc 110'is frictionally mounted on the alarm spring shaft 101 in front of this plate. It has an ascending cam surface 110a which cooperates with a lifting pin 111 fixed in the control lever 106 in such a manner that in the first section of the control cam 1 the control lever 106 remains uninfluenced and therefore its finger 1060 can cooperate with the star wheel 108. The cam disc also has an arm 11% the inner edge of which cooperates with an abutment nose 112 provided on the side wall of the hammer 105 and serving as a damping abutment. As long as the control disc 110 is in the position shown in FIGURE 1, the hammer 105 cannot swing outwardly since it is prevented by the part 11%. When the cam disc 110 has rotated sufliciently, the control lever 106 will be pulled back so that it vn'll be out of contact with the star wheel 109 whereby it will not influence the swinging movement of the hammer 105. This damping abutment is shorter than the above-mentioned first section of the ascending surface 1100 so that initially damped single hammer strokes and then undamped single hammer strokes strike the gong until the second section of the lifting cam 110a abuts against the lifting pin 111 and shifts the control lever 106 in transverse direction so that its point 1060 is moved out of the range of the cam star wheel 108.

To determine the initial position of the cam disc 110 it is provided on its periphery with abutment noses 110a and 110d and a frame post nut 113 serves as a counter abutment.

The two abutments of the control disc which must be kept in mind is abutment 110a and the second abutment can be seen in FIG. 1 between the reference characters 112 and 109. FIG. 1 shows a control disc 110 in the position in which the alarm mechanism spring is wound up. Full alarm occurs whenthe said second abutment engages the fixed aboutment 113 whereby the cam 110a pulls back the pin 111 such that the end of the control lever 1060 is not impeded by the wheel 108.

One therefore realizes that such a very little regular rotation of the control disc 110 is used for controlling the 'kind of alarm strokes and that a non exact setting of the control disc 110 which can occur under certain conditions is detrimental.

As already mentioned, several factors added together might cause the abutment nose 11% to remain at such a distance from the abutment nut 113 when the mechanism is fully wound, that a considerable portion of the effective range of the ascending cam surface 11021 is already used up when the alarm mechanism is tripped. To overcome this objection a sleeve 116 is loosely slipped onto the shank 114 of the alarm mechanism winding key 115-. This key is provided with a knurled manipulating flange 116a which is located outside the rear wall of the alarm clock case so that it can be gripped and turned with the thumb and index finger. The inner end face of the sleeve 116 has a recess 11Gb of a width and length corresponding to a catch pin 117 riveted into the control disc 110. It is possible with this arrangement to turn the control disc 110 in counterclockwise direction after the mechanism has been wound, until the nose 110a comes into contact with the not 113. This ensures that the alarm stage for the single strokes will operate for its full period.

However, to save the user of the alarm clock the trouble of manipulating the setting sleeve 116 each time, this sleeve can have an indicator or hand thereon and a mark can be provided on the rear wall of the clock case so that the relative positions of the indicator and mark will show whether the abutment nose 110c has stopped short at an undesirable distance from its abutment 1.13 when the alarm mechanism is fully wound. In a similar manner a mark serving as indicator could also be pro vided on the manipulating flange 116.

I claim:

1. An alarm clock mechanism comprising an alarm ringing hammer, a device for initially retarding the rate of the strokes of the alarm ringing hammer, a spring shaft, a control member coupled by friction with the spring shaft of the alarm mechanism and provided with two abutments angularly displaced by an angle of less than a rigid abutment fixed on a frame of the clock movement, one of said abutments of the control member striking against the rigid abutment when the alarm mechanism is being wound and the other of said abutments of the control member striking against the said rigid abutment when the alarm mechanism is released and the control member has reached a position in which the strokes of alarm are not retarded, and a manipulating sleeve on the spring shaft accessible from the outside of the clock and coupled with the control member so that the latter can be brought into contact relative to the rigid abutment.

2. An alarm clock mechanism comprising an alarm ringing hammer, a device for intially retarding the rate of the strokes of the alarm ringing hammer, a spring shaft, a control member coupled by friction with the spring shaft of the alarm mechanism and provided with two abutments angularly displaced by an angle of less than 180, a rigid abutment fixed on a frame of the clock movement, one of said abutments of the control member striking against the rigid abutment when the alarm mechanism is being wound and the other of said abutments of the control member striking against the said rigid abutment when the alarm mechanism is released and the control member has reached a position in which the strokes of alarm are not retarded, a sleeve rotatably mounted on the spring shaft and having a manipulating flange extending from the sleeve, and a coupling pin mounted on the control member, said sleeve having a recess therein in its inner end face adapted to cooperate with the coupling pin whereby the control member can be set relative to the rigid abutment.

3. An alarm clock mechanism comprising an alarm ringing hammer, a derive for initially retarding the rate of the strokes of the alarm ringing hammer, a spring shaft, a control member coupled by friction with the spring shaft of the alarm mechanism and provided with two abutments angularly displaced by an angle of less than 180, a rigid abutment fixed on a frame of the clock movement, one of said abutments of the control member striking against the rigid abutment when the alarm mechanism is being wound and the other of said abutments of the control member stniking against the said rigid abutment when the alarm mechanism is released and the control member has reached a position in which the strokes of alarm are not retarded, a sleeve rotatably mounted on the spring shafit and having a manipulating hand-1e extending from the sleeve, and a coupling. pin mounted on the control member, said sleeve having a recess therein in its inner end face adapted to cooperate with the coupling pin whereby the control member can be set relative to the rigid abutment.

References Cited in the file of this patent UNITED STATES PATENTS Kardos July 11, 1916 Junghans et a1. Jan. 15, 1957 FOREIGN PATENTS Australia Dec. 7, 19 53 

